Implantable medical devices including elongated conductor bodies that facilitate device and lead configuration variants

ABSTRACT

Implantable medical devices include elongated conductor bodies and related features including an attachment to the medical device at one end and a connector that receives a medical lead at the other end. The connector may have various features such as a modular design whereby the connector is constructed from a series of stacked contact modules. Other features of the connector include electrical contacts that are relatively thin conductors or the order of 0.040 inches or less and that may include radial protrusions to establish contact with the electrical connectors of the lead. Furthermore, electrical contacts may be mounted within the connector in a floating manner so that radial movement of the electrical contact may occur during lead insertion. Additional features include a feedthrough where conductors exposed beyond a housing of the implantable medical device make direct electrical connection to conductors present within the elongated body.

RELATED APPLICATIONS

The present application claims priority to U.S. Provisional Application61/256,548, entitled IMPLANTABLE MEDICAL DEVICES INCLUDING ELONGATEDCONDUCTOR BODIES THAT FACILITATE DEVICE AND LEAD CONFIGURATION VARIANTS,filed on Oct. 30, 2009, which is incorporated by reference herein.

TECHNICAL FIELD

Embodiments relate to implantable medical devices. More particularly,embodiments relate to implantable medical devices that include elongatedconductor bodies that facilitate connector configuration variants ofleads and devices.

BACKGROUND

Implantable medical devices (IMD) such as cardiac and neural stimulatorsutilize circuitry within an enclosure to generate electrical stimulationpulses. The circuitry is electrically linked to contacts within a headerthat is attached to the enclosure by a set of conductive pins known as afeedthrough. The implantable medical leads are physically connected tothe header and include connectors on a proximal end that engage theelectrical connectors within the header. The implantable medical leadsalso include electrodes near a distal end with the conductors carryingthe stimulation pulses from the connectors to the electrodes.

The number of leads needed for a particular therapy and correspondingIMD may vary as may the number of electrical connections per lead. Hencethe design of the header must also vary to accommodate the feedthroughof a given device and the number of leads and lead connectors that arenecessary. For example, 24 electrodes may be configured in numerous waysfor a device and therapy. One neurostimulator may drive eight electrodesper lead for three leads. Another neurostimulator may drive eightelectrodes per lead for two leads and four electrodes per lead for twoadditional leads. Yet another neurostimulator may drive twelveelectrodes per lead for two leads.

In these variations, entirely different header designs are used. Suchheader designs conventionally use ribbon bonds and lead frames as theinterconnection between the feedthrough and the pressure contact, oftena canted-coil spring, in the header. The development and resultingdesign for the ribbon bonds, lead frames, and related feedthrough becomevery specific for each IMD model and related leads and do not directlytransfer to other IMD models and leads. Furthermore, the manufacturingprocesses to construct the headers having distinct designs for thedifferent IMD models can be challenging. Thus, the development andmanufacturing processes for headers being designed for each of the IMDmodels is burdensome.

In addition to the burdens of development and manufacturing, the designsthat involve a relatively large number of pressure contacts in theheader per lead can be troublesome. Typically, the pressure contactssuch as the canted-coil springs can necessitate a large insertion forcewhen numerous pressure contacts are needed for a particular lead. Theinsertion force may exceed the capabilities of the lead to maintainphysical integrity. Lead insertion may be difficult and lead damage mayalso occur during insertion.

Additionally, because the header is rigidly attached to the IMDenclosure, the insertion of each lead requires some degree ofmanipulation of the IMD to correctly align the lead with the leadpassageway of the header. This becomes progressively more burdensome asleads are sequentially inserted and begin to crowd and clutter the areaimmediately adjacent the entryway to the header.

Furthermore, the size of the header is directly related to the connectorspacing on the lead, or lead pitch. As the number of electrodes per leadincreases the header size increases, and the increase may be significantdue to the relatively large size of conventional electrical contactssuch as the canted-coil springs. This relationship contradicts theefforts to develop smaller IMDs which are often more desirable forimplantation.

SUMMARY

Embodiments address issues such as these and others by providing variousfeatures for one or more elongated conductor bodies installed on an IMD.For instance, in some embodiments, the elongated body may have aconnector on a distal end where that connector may be constructed ofindividual modules that may be stacked together to form a passageway forthe lead within the connector. The modules may have a particular designfor a lead passageway that is replicated from one connector design tothe next to produce the desired number of lead passageways for aparticular IMD and therapy. Electrical contacts may be provided betweenvarious modules so that the number and placement of the electricalcontacts may be easily selected and varied from one connector design tothe next.

In some embodiments, the electrical contacts of the connectors may havea design that allows several modules to be stacked while retaining arelatively small contact spacing known as pitch and while retaining arelatively small insertion force requirement. The electrical contactsmay be in the form of a contact conductor that surrounds the leadpassageway while having a relatively small thickness in the axialdimension of the lead passageway, such as on the order of 0.040 inchesor less. The electrical contacts may include multiple radial protrusionsspaced about the electrical contact. These radial protrusions may engagethe electrical connectors on a lead being inserted into the leadpassageway of the connector.

Furthermore, in some embodiments, the electrical contacts may floatwithin the lead passageways of the connectors. The ability to float withsubtle radial movements during insertion better aligns the contact tothe lead connectors. As the proximal end of the lead and the series oflead connectors on the proximal end may have concentricityimperfections, the floating electrical contact further lessens insertionforce requirements.

In some embodiments, the one or more elongated bodies may connect to theIMD enclosure by providing a boot that receives a proximal end of eachof the one or more elongated bodies and that surrounds the feedthroughof the IMD. Electrical conductors introduced into the boot via thefeedthrough provide a direct connection to the electrical conductors inthe elongated body to avoid intervening conductors and relatedconnections.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an implantable medical device including an embodiment of aharness that includes a boot, elongated body, and connector.

FIG. 2 shows a perspective view of an embodiment of the connector of theharness.

FIG. 3 shows an exploded perspective view of contact modules of anembodiment of the connector.

FIG. 4A shows an exploded perspective view of a contact module,electrical contact, and contact isolator of an embodiment of theconnector.

FIG. 4B shows an alternative electrical contact.

FIG. 5 shows a perspective view of an arrangement of electrical contactsand contact isolators with the contact modules being omitted forclarity.

FIG. 6 shows a perspective cross-sectional view taken through anembodiment of a connector.

FIG. 7 shows a top view normal to the plane of the cross-section of FIG.6 and with a medical lead being fully inserted into the connector.

FIG. 8 shows a cross-sectional perspective view of one example of theboot positioned about a feedthrough of the implantable medical device.

FIG. 9 shows a perspective view of the feedthrough and relatedconductors with the boot omitted for clarity.

FIG. 10 shows a perspective view of the feedthrough and relatedconductors with the boot and cable sleeves omitted for clarity.

FIG. 11 shows a top view of the feedthrough and related conductors withthe boot and cable sleeves omitted for clarity.

FIG. 12 shows a side view of the feedthrough and related conductors withthe boot and cable sleeves omitted for clarity.

FIG. 13 shows a back view of the feedthrough and related conductors withthe boot and cable sleeves omitted for clarity.

DETAILED DESCRIPTION

Embodiments provide for implantable medical devices that include ahousing, an elongated body that extends from a connection to thehousing, and a connector attached to an end of the elongated body thatreceives a medical lead. This combination of the elongated body and theconnector allows for device and lead configuration variants. Embodimentsof the connector may be modular whereby contact modules of a particulardesign may be stacked to achieve the number of electrical contacts thatare necessary for a given device and lead configuration. Furthermore,the number of elongated bodies that extend from a connection to thehousing may vary to accommodate the number of leads that are necessaryfor a given device configuration.

Embodiments of the connection of the elongated body to the housing maysimplify connectivity relative to a conventional header design byproviding for direct electrical connections between electricalconductors of the elongated body and the feedthrough conductors of thedevice. The feedthrough conductors may be exposed within a boot thatprovides the attachment of the elongated body to the device to achieveelectrical connection to the electrical conductors of the elongatedbody, and ultimately to the electrical contacts of the connector.

Embodiments of the connectors may allow for a relatively large number ofelectrical connections for a given lead by providing relatively thinelectrical contacts, on the order of 0.040 inches or less in the axialdimension in addition to providing the connector at the end of theelongated body that extends from a connection to the housing. The thinnature of the electrical contacts reduces the axial space needed for alarge number of electrical connections to a lead.

Embodiments of the connectors may allow for a relatively large number ofelectrical connections for a given lead by reducing scraping forces thatoccur during lead insertion. The reduction may be provided by the thinand flexible nature of radial protrusions of some embodiments of theelectrical contacts within the connector. The reduction may beadditionally or alternatively provided by allowing the electricalcontact to radially float within the connector to better align withconcentricity variations of the lead.

FIG. 1 shows one example of an implantable medical device (IMD) 100. TheIMD 100 includes a housing 102 that encloses medical circuitry 116 thatis used to provide the medical function of the IMD 100. The medicalcircuitry 116 may include various components such as one or morebatteries, controllers, pulse generators, and the like. The housing 102is typically constructed of biocompatible materials such as variousgrades of titanium. The IMD 100 is typically implanted at a site withina patient's body or may be mounted externally of the body in someinstances.

The IMD 100 includes a feedthrough 112 that exposes electricalconductors externally of the housing 102. The electrical conductors maybe the ends of the electrical pins 114 that exit the medical circuitry116. Alternatively, the electrical conductors exposed by the feedthrough112 may be electrical contact pads that are electrically connected tothe pins 114.

The IMD 100 also includes a boot 104 that is mounted to the housing 102in a sealed relationship that resists body fluids from penetrating intothe junction to the housing 102. The boot 104 receives the electricalconductors exposed beyond the housing 102 via the feedthrough 112. Theboot 104 also receives a proximal end of one or more elongated bodies106.

The elongated body 106 may be flexible like a conventional medical leadand is attached at a distal end to a connector 108 that receives amedical lead 110. In some embodiments, the length of the elongated body106 may be significantly less than that of a conventional medical leadso that the connector 108 is in close proximity to the housing 102. Insuch a case, the medical leads 110 may be implanted in the normal mannerwith the proximal end of the medical lead 110 inserted into theconnector 108 rather than being inserted into a conventional header.

The connector 108 may include various structures for fixing the positionof the medical lead 110, such as set screw blocks and the like. The setscrew block or other manner of fixing the medical lead 110 may belocated within a contact module of the connector 108, for instance themost distal contact module. The medical lead 110 that is inserted intothe connector 108 has electrical connectors on the proximal end,electrodes on a distal end, and conductors that interconnect the two.

The connector 108 includes electrical contacts, discussed in more detailbelow, that contact corresponding electrical connections of the medicallead 110. These electrical contacts are also in electrical communicationwith corresponding electrical conductors within the elongated body 106and carry electrical signals between the electrical connections of thelead 106 and the electrical conductors of the elongated body 106. Theelectrical conductors of the elongated body 106 carry the electricalsignals between the feedthrough conductors and the electrical contactsof the connector 108.

FIG. 2 provides a view of the internal components of one embodiment ofthe connector 108. These components include a series of contact modules120 that are stacked to create the axial dimension of the connector 108.It should be noted that the contact modules 120 being stacked refers tobeing positioned immediately adjacently to one another without regard tohorizontal or vertical orientation of the stack. The contact modules 120may be constructed of various non-conductive materials that ultimatelyprovide a rigid structure such as injection molded plastics. The contactmodules 120 house other components such as the electrical contacts ofthe connector 108. Once these components are installed relative to thecontact modules 120, the contact modules 120 may be stacked together inthe length needed for a particular device and lead configuration. Thecontact modules 120 may also then be fused by a process such as anultrasonic weld or adhesive bonding to create one rigid and sealedconnector body. The stacking and sealing may be done by holding eachmodule relative to a common reference point to improve the dimensionaltolerance of the final assembly.

FIG. 2 also shows additional features. A lead passageway 122 isestablished by each of the contact modules 120 and ultimately theconnector 108. Additionally, each contact module 120 includes a set ofcircumferentially spaced channels 126.

Electrical contacts are present within the connector 108 and arediscussed in more detail below with reference to FIGS. 3-7. Each ofthese electrical contacts includes an extension 124 that exits fromwithin the connector 108 and rests within one of the channels 126 thatis dedicated to that particular extension 124. The extension has alength that matches the distance from the electrical contact to theproximal end of the connector 108 so that while each electrical contacthas a different distance to the proximal end, each extension 124 ends atthe same point in the axial direction.

In this example, bridging conductors 125 are either formed integrally atthe ends of the extensions 124 or may be separate conductors attached tothe ends of the extensions 124 such as by a friction fitting or a weld.However, it will be appreciated that the bridging conductors 125 may beintegral to the extensions 124. The bridging conductors 125 electricallyconnect the extensions 124 to corresponding connectors within theelongated body 106. These connectors and conductors within the elongatedbody 106 are discussed in more detail below with reference to FIG. 7.

While the contact modules 120 are visible in FIG. 2, the series ofcontact modules 120 forming the connector 108 may be encapsulated in apolymer shell. This may be beneficial for embodiments where the channels126 are otherwise exposed. The polymer shell may seal the channels 126so that the extensions 124 are not exposed to ambient conditions aboutthe connector 108, which prevents conductive bodily fluids from shortcircuiting the extensions 124 that originate from different electricalcontacts within the connector 108. As an alternative to, or in additionto the polymer shell, the extensions 124 may be coated with anon-conductive material, such as polytetrafluoroethylene (PTFE) orethylene tetrafluoroethylene (ETFE) to prevent shorting circuitingbetween extensions 124.

The connector 108 also includes an end cap module 121. This module 121terminates the lead passageway 122 by providing a blunt distal end tothe connector 108. The connector 108 is further discussed below withreference to FIGS. 6 and 7.

FIG. 3 shows an exploded view of the connector 108 and each of thecomponents of this particular embodiment. The lead passageway 122 ofeach contact module 120 receives a corresponding contact isolator 128.The lead passageway 122 of each contact module 120 also receives acorresponding electrical contact 132. The contact isolator 128 ispresent to provide a sealing engagement to the insulator of the leadbody that is present between electrical connectors of the lead 110. Thissealing engagement provides a degree of isolation between the series ofelectrical contacts 132 of the connector 108 so that the distinctelectrical pathways are less likely to become electrically shorted byconductive bodily fluids that are present about the connector 108.

FIG. 4A shows the contact module 120, contact isolator 128, andelectrical contact 132 according to this particular embodiment. Thecontact module 120 has a set of axial extensions 154 that upon assemblyenter the lead passageway 122 of the adjacent contact module 120. Thisengagement of the axial extensions 154 to the lead passageway 122 aidsin properly aligning the contact modules 120 and also providesstructural support for the connector structure 108 by stabilizing theposition of one contact module 120 relative to an adjacent one bothbefore and after fusing of the contact modules 120.

In this embodiment, the contact module 120 may have various featuresthat relate to the electrical contact 132. The axial extensions 154 arearranged circumferentially and define spaces 156 that accommodate theelectrical contact 132. The electrical contact 132 of this embodiment isa thin conductive ring with radial protrusions 142. These radialprotrusions 142 reside within the spaces 156 as the electrical contact132 is placed about the axial extensions 154 to surround the leadpassageway. The contact module 120 may include a recess 162 that allowsthe electrical contact 132 to rest in place between adjacent contactmodules. The recess 162 may join with the specific channel that receivesthe axial extension 124 of the electrical contact 132 to allow the axialextension 124 to exit from the interior of the contact module 120.

The electrical contact 132 of this particular embodiment utilizes theradial protrusions 142 to establish physical and electrical contact withthe electrical connectors of the lead 110. In the example shown, thereare four radial protrusions, each having a U shape with the bend of theU shape providing the contact surface. This relatively small point ofcontact may be useful to lessen the scraping force that occurs duringlead insertion. Furthermore, the radial protrusions may be provided witha degree of flexibility so that they may deflect slightly in the axialdirection to further reduce scraping forces and to snugly engage theelectrical connectors of the lead 110.

An additional feature of the electrical contact 132 relevant to leadinsertion may be a radial floating relationship to the contact module120. This radial floating relationship may be provided by havingelectrical contact 132 with an inner diameter that is greater than theouter diameter established by the axial protrusions 154. An outerdiameter of the electrical contact 132 may be less than the outerdiameter established by the recess 162. The spacing between axialextensions 154 of a set may be greater than the width of the radialprotrusions 142. As a result of these size relationships, a degree offreedom in the radial direction is established for the electricalcontact 132 that allows the electrical contact 132 to better accommodateconcentricity imperfections in the lead 110 as it is being inserted.

The electrical contact 132 may be constructed of various conductivematerials such as titanium, titanium alloys, MP35N, and the like. Theelectrical contacts may be of various sizes; however, a thicknessranging from 0.004 to 0.040 inches may have adequate structuralintegrity while offering the benefit of reduced scraping force. For theelectrical contact 132 as shown, the thickness may range from 0.004 to0.020 inches so that the resulting thickness of the radial protrusionranges from 0.008 to 0.040 inches. Furthermore, the thin nature of theelectrical contact may allow for a relatively small center-to-centerspacing of electrical contacts known as lead pitch, such as 0.080 inchesor less.

While the electrical contact 132 of a particular design is shownrelative to the contact module 120, it will be appreciated that otherelectrical contact designs are also applicable to a connectorconstructed from a series of contact modules. Likewise, while aparticular connector design employing a series of contact modules isshown, it will be appreciated that other connector designs includingnon-modular designs are also applicable for use of thin electricalcontacts with radial protrusions.

FIG. 4B shows an alternative electrical contact 133. This electricalcontact 133 is a wireform that also is within and surrounds the leadpassageway 122 and is contained by axial extensions of a contact module.The axial extensions that cooperate with the electrical contact 133 areshaped to fit the particular wireform shape, as opposed to having theshape shown in FIG. 4A. The wireform electrical contact 133 may be sizedto float in the manner as the electrical contact of FIG. 4A. Thewireform electrical contact 133 may also have a thickness in the axialdirection on the order of 0.004 to 0.040 inches.

In this particular example, the wireform electrical contact 133 is inthe shape of a shamrock and includes four radial protrusions 143 toestablish points of contact on the electrical connector of the lead 110.However, it will be appreciated that other wireform shapes areapplicable such as a triangular shape, diamond shape, and the like wheresmall points of contact to the lead connector are established by thelinear regions of the shape rather than by radial protrusions. Thewireform electrical contact 133 also includes an extension 123 that mayextend along a channel 126 until reaching the proximal end of theconnector 108.

FIG. 4A also shows the contact isolator 128 which is positioned withinthe lead passageway 122 to form a seal at the point of contact with thecontact modules 120. These contact isolators include an aperture 140through which the lead 110 passes during insertion into the connector108. The aperture 140 may have a diameter that is slightly less thanthat of the lead 110. Furthermore, the contact isolator 128 may beconstructed of an elastic material such as silicone rubber so that theaperture expands during lead insertion and forms a tight seal againstthe lead body to reduce the likelihood of bodily fluids creating aconductive path from one electrical contact of one contact module to anelectrical contact of an adjacent module.

The contact isolator 128 is elastic while the contact module 120 isrigid and thus the two types of components may be manufacturedseparately as shown. However, a co-injection molding process may insteadbe used to form the contact isolator 128 from an elastic materialtogether with the contact module 120 from a rigid material together asone piece.

FIG. 5 shows a view of the connector components but with the contactmodules 120 omitted for clarity of illustration. This view illustratesthe relative placement of the electrical contacts 132, extensions 124,bridging conductors 125, and contact isolators 128. Here it can be seenthat each electrical contact 132 is axially between a pair of axiallyspaced contact isolators 128 on each side to provide a sealed space foreach electrical contact 132. The differing lengths of the extensions 124that result in the extensions terminating at the same point on theproximal end of the connector 108 can also be seen.

FIG. 6 shows a cross-sectional perspective view of this example of aconnector 108. FIG. 6 provides a reference for viewing FIG. 7. FIG. 7 isa top view of the connector 108 and includes the lead 110 in a fullyinserted position.

FIG. 7 shows electrical connectors 170 of the lead 110. FIG. 7 alsoshows the insulator section 172 of the lead 110 that is positionedbetween electrical connectors. FIGS. 6 and 7 show the containment of theelectrical contacts 132 and contact isolators 128 within the contactmodules 120. It can be seen that the contact isolators 128 arepositioned between an end of the axial extensions of one contact moduleand an inner abutment of an adjacent contact module.

FIGS. 6 and 7 show the presence of the radial protrusions 142 of theelectrical contacts 132 relative to the lead passageway 122, and FIG. 7shows the electrical connection of the radial protrusions 142 to theelectrical connectors 170 of the lead 110. In this particular example,as shown in FIG. 4A, there are four radial protrusions 142 andcorresponding spaces 156 defined by the axial protrusions 154, and thesefeatures shift by 45 degrees relative to the radial protrusions andspaces of adjacent electrical contacts and contact modules. As a result,the radial protrusions 142 are visible in the cross-section only atevery other contact module 120. This shift allows the extension 124 ofone electrical contact to have a dedicated channel 126 and be separatedby 45 degrees from an extension 124 of an adjacent contact module 120that lies within the next channel. It will be appreciated that theradial protrusions 142 may be at other angles as may the spacing fromthe axial extensions for those embodiments that include axialextensions, particularly where the number of radial protrusions 142and/or the total number of electrical contacts 132 differ from thenumber shown.

FIG. 7 further shows the contact isolators 128 within the leadpassageway 122 making physical contact with the insulator sections 172of the lead 110. As discussed above, this contact establishes a seal oneach side of each electrical contact to electrical connector pairing toreduce the likelihood of fluid conducting between adjacent electricalcontacts.

FIGS. 6 and 7 further show the end cap module 121 which provides a bluntend to the connector 108. The end cap module 121 of this example omitsthe axial extensions 154 and the recess 162. As shown in FIG. 7, the endcap 121 as well as the remainder of the connector 108 may beencapsulated in a polymer layer 150 to further seal and stabilize theconnector 108.

FIG. 7 further shows connectivity of the bridge conductors 125 to theconductors of the elongated body 106. In this particular example, thebridge conductors 125 pass through an end plate 164 that separates theelongated body 106 from the connector 108. The end plate 164 of thisexample includes a set of conductive coils 166, one for each bridgeconductor 125. The bridge conductor 125 rests within the respective coil166 where an interference fit may provide a snug physical and electricalconnection and/or a weld may be done to establish a physical andelectrical connection. Electrical conductors 168 within the elongatedbody 106 are attached to the conductive coils 166 either by a similarinterference fit to the coils 166 or by other attachments such as a weldor other bond.

There may be various benefits for some embodiments having each extension124 terminate via the bridge conductors 125 at the proximal end of theconnector 108 where connection is made to the elongated body 106. Forinstance, the conductors 168 of the elongated body 106 may terminate atthe end of the elongated body 106 rather than extending from the bodyand into the connector 108 which may simplify some aspects ofconstruction of the connector 108. This may also simplify the electricalconnection of the conductors 168 to the contacts 132 of the connector108. This also allows the conductors 168 to be of an entirely differentconstruction and type of material than the extensions 124 if desired,such as using coiled conductors 168 within a lumen of the elongated body106 while using straight extensions 124.

While the example of FIGS. 1-7 has shown a single connector 108 with asingle lead passageway 122 for a single lead 110, it will be appreciatedthat multiple leads can be accommodated. For instance, the boot 104 mayprovide a point of attachment of multiple elongated bodies with eachelongated body providing a connector that receives at least one lead. Asanother example, the connector may have multiple lead passageways tothereby accept multiple leads.

FIG. 8 shows a cross-sectional perspective view of one example of theboot 104 for an example of the IMD 100. The boot 104 surrounds thefeedthrough 112 that passes through the housing 102. The housing 102 mayprovide a mounting post 174 or other similar feature upon which the boot104 may reside to be held in place about the feedthrough 112. The boot104 may include an aperture 179 that exposes the feedthrough 112 forpurposes of establishing electrical connections via welds betweenfeedthrough conductors such as the electrical contact pads 176 of thefeedthrough 112 and conductor portions 178 within the boot 104. The boot104 may be encapsulated in a polymer once assembly is complete to sealthe boot 104 including the connection of the conductor portions 178 tothe contact pads 176. To the extent the electrical connections betweenconductor portions 178 and contact pads 176 are established beforeattachment of the boot 104, then the boot 104 may omit the aperture 179and the encapsulation may be omitted.

In this particular view, only eight conductor portions 178 are shown.However, the feedthrough 112 may provide any number of contact pads 176and in this example, 24 contact pads 176 are present to support up to 24electrical contacts of one or more connectors 108. As can be seen, theconductor portions 178 occupy no more space axially than the contactpads 176 so that the boot 104 is sized to fit about the feedthrough 112and occupy a relatively small amount of space on the housing 102 incomparison to a conventional header. As a result, the reduction in sizeof the housing 102 is not as limited by the size of the boot 104 as itwould be limited by the size of a conventional header.

The boot 104 may be molded with the proximal end of the elongated bodyand related conductors in place so that the boot 104 holds the wiring ina proper orientation and with a proper spacing needed for assembly. Asdiscussed below with reference to FIG. 9, the conductors of theelongated body that are present within the boot align with thefeedthrough conductors such as the contact pads 176 so that physical andelectrical attachment can be completed. The boot 104 being molded overthe elongated body and conductors may facilitate that assembly process.

FIG. 9 shows the IMD 100 with the boot 104 removed to reveal thepresence of individual elongated bodies 180. These elongated bodies 180are in the form of cables carrying the individual conductors and mayextend within the elongated body 106 to the one or more connectors 108present at the distal end of the elongated body 106. Alternatively, eachelongated body 180 may serve as the elongated body 106 by exiting theboot 104 and having a dedicated connector 108 at the distal end.

In the example of FIG. 9, each elongated body 180 includes sixindividual conductors, such as the conductors 168 shown in FIG. 7, wherethe conductor portion 178 of each conductor 168 exits the elongated body180 to establish a bond to the corresponding contact pad 176. There arefour elongated bodies 180 for a total of 24 conductors 168 and conductorportions 178 so that all of the contact pads 176 have a bonded conductorportion 178 and are available for use by the medical circuitry 116.

The proximal end of the elongated bodies 180 in this particular exampleof FIG. 9 are covered by cable sleeves 182. The sleeves 182 contain theindividual conductors 168 while allowing the conductor portions 178 ofthe individual conductors 168 to exit the sleeve 182 in the direction ofthe feedthrough 112. In this example, the sleeves 182 terminate inproper alignment with the relevant section of the feedthrough 112 sothat the conductor portions 178 are properly aligned with thecorresponding contact pads 176 upon exiting the sleeve 182 in thedirection of the feedthrough 112.

Where the sleeve 182 is formed over conductors 168 to properly orientand align them relative to the contact pads 176, then the conductorportions 178 may be attached to the contact pads 176 prior to placementof the boot 104. In that case, the boot 104 may be formed over thesleeves 182 without including an aperture 179. The boot 104 therebyholds the sleeves in position as opposed to the boot 104 directlyholding each conductor 168 in position.

FIGS. 10-13 show various views of the IMD 100 with the boot 104 and thesleeves 182 removed. These views further reveal the coiled collection184 of the individual conductors 168 from FIG. 7 that are present withineach of the elongated bodies 180, the distal end 186 of the coiledcollection 184 being shown in FIG. 13. The conductor portion 178 feedsinto the collection of conductors 168 in a coiled manner for creating acompact collection of conductors contained within the elongated bodies180. The coiled collection 184 may be beneficial to provide strainrelief and the ability to stretch, align, and orient conductors 168 sothat the conductor portions 178 align with the pads 176. The individualconductors 168 of the coiled collection 184 may be coated with aninsulator such as ETFE or PTFE to prevent the individual conductors 168from creating short circuits.

Various features of the illustrative embodiments are applicable in otherembodiments independently of other features disclosed herein. Forinstance, the modular construction of the connector may be achieved byusing contact modules but while not necessarily using other features. Asone example, the modular connector may be constructed of contact moduleswhile the attachment to the device utilizes a more conventional header,such as where the elongated body has significant length and is utilizedas a lead extension. As another example, the modular connector may beconstructed of contact modules that accommodate conventional cantedspring connectors that may or may not float.

The direct connection of feedthrough conductors to electrical conductorsof the elongated body may be achieved while not necessarily using otherfeatures. As one example, the direct connection of feed throughconductors to electrical conductors may be present where a non-modularconnector construction is used on the other end of the elongated body.As another example, the direct connection of feedthrough conductors andelectrical conductors of the elongated body may be present where theconnector has electrical contacts that are mounted within the connectorin a fixed, non-floating manner.

The relatively thin electrical contacts with or without radialprotrusions may be used while not necessarily using other features. Asone example, these electrical contacts may be present within anon-modular connector construction that accepts these electricalcontacts in a fixed or floating manner. As another example, theseelectrical contacts may be present where the attachment of the elongatedbody to the device utilizes a more conventional header.

Furthermore, the floating nature of the electrical contacts may be usedwhile not necessarily using other features. For example, an electricalcontact may float within a non-modular connector construction and therecessed area where the electrical contact is present provides freedomof movement in a radial direction. As another example, an electricalcontact may float within a connector where the attachment of theelongated body to the device utilizes a more conventional header. Asanother example, an electrical contact may float within a connectorwhile having a different design than being relatively thin with radialprotrusions.

Embodiments provide an implantable medical device that includes ahousing, circuitry within the housing, a feedthrough electricallyconnected to the circuitry and providing a plurality of feedthroughconductors externally of the housing, and an elongated body having aproximal end and a distal end. A plurality of conductors is located inthe body, the plurality of conductors being electrically coupled to thefeedthrough conductors in proximity to the proximal end of the body. Aconnector is attached to the distal end of the body, and the connectorincludes a plurality of adjacent contact modules, each contact modulehaving at least one lead passageway. A plurality of contact isolatorsare included within the connector, with a contact isolator of theplurality being disposed within each of the at least one leadpassageways of the corresponding contact modules of the plurality. Aplurality of electrical contacts are included within the connector andare positioned within the lead passageway, with at least one electricalcontact of the plurality being located axially between contactisolators, each of the plurality of contacts being in electricalcommunication with at least one of the conductors.

Each contact module of this implantable medical device embodiment mayhave axial extensions spaced circumferentially on a first end, theplurality of contact modules being stacked so that an axial extension ofone contact module fits into the lead passageway of an adjacent contactmodule. Each contact isolator of the plurality may be present between anabutment within the at least one lead passageway of the correspondingcontact module and an end of the axial extensions of an adjacent contactmodule that are present within the at least one lead passageway of thecorresponding contact module. Each electrical contact of the pluralitymay be disposed about the axial extensions of the plurality of contactmodules.

Each of the electrical contacts of this implantable medical deviceembodiment may include an extension that is present within a channel ofthe contact modules, extends along the channel of the plurality ofmodules toward the body and is electrically connected to one of theelectrical conductors of the body. The connector may be encapsulated ina polymer. Each of the electrical contacts may surround the leadpassageway and may include flexible radial protrusions. The plurality ofadjacent contact modules may be fused. At least one contact isolator ofthe plurality may be co-molded with a corresponding contact module. Eachcontact isolator may be a ring made of a material such as siliconerubber.

Embodiments provide for an implantable medical device that includes ahousing, circuitry within the housing, and a feedthrough electricallyconnected to the circuitry and providing at least one feedthroughconductor externally of the housing. A harness may be mounted to thehousing, the harness including a boot attached to the housing about thefeedthrough and receiving the at least one feedthrough conductor. Atleast one elongated body having a proximal end attached to the boot andhaving a distal end may be included in the harness. At least oneconductor in the at least one body may be included in the harness, theat least one conductor being electrically coupled to the at least onefeedthrough conductor. A connector attached to the distal end of the atleast one body may be included in the harness, the connector comprisinga lead passageway and at least one electrical contact within the leadpassageway that is in electrical communication with the at least oneconductor.

The feedthrough of this implantable medical device embodiment mayprovide a plurality of feedthrough conductors and the boot may receivethe plurality of feedthrough conductors. The harness may further includea second elongated body having a proximal end attached to the boot andhaving a distal end. At least one conductor may be included in thesecond body, the at least one conductor being electrically coupled to atleast one of the plurality of feedthrough conductors. A connector may beattached to the distal end of the second body, the connector including alead passageway and at least one electrical contact within the leadpassageway that is in electrical communication with the at least oneconductor in the second body.

The connector of this implantable medical device embodiment may furtherinclude a plurality of adjacent contact modules, each contact modulehaving at least one lead passageway. A plurality of contact isolatorsmay be included within the connector, with a contact isolator of theplurality being disposed within each of the at least one leadpassageways of the corresponding contact modules of the plurality. Theplurality of electrical contacts may be positioned within the at leastone lead passageway, with at least one electrical contact being locatedaxially between contact isolators.

Each contact module of this implantable medical device embodiment hasaxial extensions spaced circumferentially on a first end, the pluralityof contact modules being stacked so that an axial extension of onecontact module fits into the lead passageway of an adjacent contactmodule. Each contact isolator of the plurality may be present between anabutment within the at least one lead passageway of the correspondingcontact module and an end of the axial extensions of an adjacent contactmodule that are present within the at least one lead passageway of thecorresponding contact module. Each electrical contact of the pluralitymay be disposed about the axial extensions of the plurality of contactmodules.

Each of the electrical contacts of this implantable medical deviceembodiment may surround the lead passageway and may include flexibleradial protrusions. The plurality of adjacent contact modules may befused. Each contact isolator may be a ring and may be made of a materialsuch as silicone rubber.

Embodiments provide an implantable medical device that includes ahousing, circuitry within the housing, a feedthrough electricallyconnected to the circuitry and providing at least one feedthroughconductor externally of the housing, and a harness mounted to thehousing. The harness may include an elongated body that has a proximalend and a distal end. At least one conductor is present in the body, theat least one conductor being electrically coupled to the at least onefeedthrough conductor in proximity to the proximal end of the body. Aconnector may be included in the harness and be attached to the distalend of the body, the connector defining at least one lead passageway andcomprising at least one electrical contact that is electrically coupledto the at least one feedthrough conductor. The at least one electricalcontact may surround the lead passageway and have a thickness in anaxial direction of 0.040 inches or less.

The electrical contact of this implantable medical device may floatradially relative to the at least one lead passageway. The connector mayfurther include a plurality of adjacent contact modules, each contactmodule having at least one lead passageway. A plurality of contactisolators may be present within the connector, with a contact isolatorof the plurality being disposed within each of the at least one leadpassageways of the corresponding contact modules of the plurality. Theplurality of electrical contacts may be positioned within the at leastone lead passageway, with at least one electrical contact being locatedaxially between contact isolators. Each contact module may have axialextensions spaced circumferentially on a first end, the plurality ofcontact modules being stacked so that an axial extension of one contactmodule fits into the lead passageway of an adjacent contact module. Eachcontact isolator of the plurality may be present between an abutmentwithin the at least one lead passageway of the corresponding contactmodule and an end of the axial extensions of an adjacent contact modulethat are present within the at least one lead passageway of thecorresponding contact module. Each electrical contact of the pluralitymay be disposed about the axial extensions of the plurality of contactmodules.

Each of the electrical contacts of this implantable medical deviceembodiment may include an extension that is present within a channel ofthe contact modules, extends along the channel of the plurality ofcontact modules toward the body, and is electrically connected to one ofthe electrical conductors of the body. The connector may be encapsulatedin a polymer. Each of the electrical contacts may include flexibleradial protrusions. The plurality of adjacent contact modules may befused. Each contact isolator may be a ring. Each contact isolator may bemade of silicone rubber.

Embodiments provide an implantable medical device that includes ahousing, circuitry within the housing, a feedthrough electricallyconnected to the circuitry and providing at least one feedthroughconductor externally of the housing, and a harness mounted to thehousing. The harness includes an elongated body that has a proximal endand a distal end. At least one conductor is present in the body, the atleast one conductor being electrically coupled to the at least onefeedthrough conductor in proximity to the proximal end of the body. Aconnector is included in the harness and is attached to the distal endof the body, the connector defining at least one lead passageway andcomprising at least one electrical contact that is electrically coupledto the at least one feedthrough conductor. The at least one electricalcontact is contained within the connector while having a radiallyfloating relationship to the lead passageway.

The connector of this implantable medical device embodiment may furtherinclude a plurality of adjacent contact modules, each contact modulehaving at least one lead passageway. A plurality of contact isolatorsmay be included, with a contact isolator of the plurality being disposedwithin each of the at least one lead passageways of the correspondingcontact modules of the plurality. The plurality of electrical contactsmay be positioned within the at least one lead passageway of theadjacent contact modules, with at least one electrical contact beinglocated axially between contact isolators.

Each contact module may have axial extensions spaced circumferentiallyon a first end, the plurality of contact modules being stacked so thatan axial extension of one contact module fits into the lead passagewayof an adjacent contact module. Each contact isolator of the pluralitymay be present between an abutment within the at least one leadpassageway of the corresponding contact module and an end of the axialextensions of an adjacent contact module that are present within the atleast one lead passageway of the corresponding contact module. Eachelectrical contact of the plurality may be disposed about the axialextensions of the plurality of contact modules.

Each of the electrical contacts may include an extension that is presentwithin a channel of the contact modules extends along the channel of theplurality of modules toward the body and is electrically connected toone of the electrical conductors of the body. The connector may beencapsulated in a polymer. Each of the electrical contacts may surroundthe lead passageway and comprises flexible radial protrusions. Theplurality of adjacent contact modules may be fused. Each contactisolator may be a ring and may be made of a material such as siliconerubber.

While embodiments have been particularly shown and described, it will beunderstood by those skilled in the art that various other changes in theform and details may be made therein without departing from the spiritand scope of the invention.

What is claimed is:
 1. An implantable medical device, comprising: a housing; circuitry within the housing; a feedthrough electrically connected to the circuitry and providing a plurality of feedthrough conductors externally of the housing; an elongated body having a proximal end and a distal end; a plurality of conductors in the body, the plurality of conductors having proximal ends at the proximal end of the elongated body with the proximal ends of the conductors being physically connected to the feedthrough so as to be electrically coupled to the feedthrough conductors in proximity to the proximal end of the body; a connector attached to the distal end of the body, the connector comprising: a plurality of adjacent contact modules, each contact module having at least one lead passageway; a plurality of contact isolators, with contact isolators of the plurality being disposed within each of the at least one lead passageways of the corresponding contact modules of the plurality; and a plurality of electrical contacts positioned within the lead passageway of each contact module, with at least one electrical contact of the plurality being located axially between contact isolators, each of the plurality of contacts being in electrical communication with at least one of the conductors.
 2. The implantable medical device of claim 1, wherein each contact module has axial extensions spaced circumferentially on a first end, the plurality of contact modules being stacked so that an axial extension of one contact module fits into the lead passageway of an adjacent contact module, wherein each contact isolator of the plurality is present between an abutment within the at least one lead passageway of the corresponding contact module and an end of the axial extensions of an adjacent contact module that are present within the at least one lead passageway of the corresponding contact module, and wherein each electrical contact of the plurality is disposed about the axial extensions of the plurality of contact modules.
 3. The implantable medical device of claim 1, wherein each of the electrical contacts includes an extension that is present within a channel of the contact modules, extends along the channel of the plurality of modules toward the body and is electrically connected to one of the electrical conductors of the body.
 4. The implantable medical device of claim 3, wherein the connector is encapsulated in a polymer.
 5. The implantable medical device of claim 1, wherein each of the electrical contacts surrounds the lead passageway and comprises flexible radial protrusions.
 6. The implantable medical device of claim 1, wherein the plurality of adjacent contact modules are fused.
 7. The implantable medical device of claim 1, wherein at least one contact isolator of the plurality is co-molded with a corresponding contact module.
 8. The implantable medical device of claim 1, wherein each contact isolator is a ring made of silicone rubber.
 9. An implantable medical device, comprising: a housing; circuitry within the housing; a feedthrough electrically connected to the circuitry and providing a plurality of feedthrough conductors externally of the housing; an elongated body having a proximal end and a distal end, the proximal end being physically coupled to the housing; a plurality of conductors in the body, the plurality of conductors being electrically coupled to the feedthrough conductors in proximity to the proximal end of the body; a connector attached to the distal end of the body, the connector comprising: a plurality of adjacent contact modules, each contact module having at least one lead passageway; a plurality of contact isolators, with contact isolators of the plurality being disposed within each of the at least one lead passageways of the corresponding contact modules of the plurality; and a plurality of electrical contacts positioned within the lead passageway of each contact module, with at least one electrical contact of the plurality being located axially between contact isolators, each of the plurality of contacts being in electrical communication with at least one of the conductors.
 10. An implantable medical device, comprising: a housing; circuitry within the housing; a feedthrough electrically connected to the circuitry and providing a plurality of feedthrough conductors externally of the housing; an elongated body having a proximal end and a distal end; a plurality of conductors in the body, the plurality of conductors being electrically coupled to the feedthrough conductors in proximity to the proximal end of the body; a connector attached to the distal end of the body, the connector comprising: a plurality of adjacent contact modules, each contact module having at least one lead passageway; a plurality of contact isolators, with contact isolators of the plurality being disposed within each of the at least one lead passageways of the corresponding contact modules of the plurality; and a plurality of electrical contacts positioned within the lead passageway of each contact module, with at least one electrical contact of the plurality being located axially between contact isolators, each of the plurality of contacts being in electrical communication with at least one of the conductors, wherein each contact module has axial extensions spaced circumferentially on a first end, the plurality of contact modules being stacked so that an axial extension of one contact module fits into the lead passageway of an adjacent contact module, wherein each contact isolator of the plurality is present between an abutment within the at least one lead passageway of the corresponding contact module and an end of the axial extensions of an adjacent contact module that are present within the at least one lead passageway of the corresponding contact module, and wherein each electrical contact of the plurality is disposed about the axial extensions of the plurality of contact modules. 